Some people would consider fitting 30Gb on a 20Gb tape optimistic. Here's
quick list of things to check that might help:
1. Are you using either software or hardware compression? If you are using
both, you could wind up with backups taking more tape than expected.
2. Is/was the tape drive in compression mode when amlabel was run? Did it
stay in compression mode?
3. Is/was the tape drive in compression mode when amdump started? Did it
stay in compression mode?
4. If you have more than one entry in your disklist, try commenting out all
but one entry. AMANDA always starts a disk she has never seen before with a
level 0 backup, and if that backup doesn't fit on tape, you're just done.
Spreading out additions to the disk list over several days helps her balance
the level 0 backups across the dumpcycle. This is where the "can't switch to
incremental" usually comes from.
5. Check your tapetype definition, and make sure that it reflects your
(approximate) compressed tape capacity, if you're using hardware
compression.
For example, if you have a tapetype that specifies the tape length as 20Gb,
AMANDA will honor that even if you could have stored 50G on that tape
because your data is very compressible. Once you are sure that hardware
compression is on (2 and 3 above) you can increase your tape size to reflect
the additional (theoretical) capacity. The best idea I've seen on how to do
this is (from JRJ, I think) to set it to the claimed capacity and expect it
to run out of tape. (AMANDA handles out-of-tape very well.) Once it runs out
of tape, you have an idea as to what sort of compression you're getting.
My shameless plug for software compression: If you use software compression
instead of hardware, you can distribute the compression load to clients
where appropriate; AMANDA can plan backups based on more accurate
information about tape size; tapes may be easier to recover in a tape drive
that isn't an exact match; you can turn compression on or off for each disk
in your disklist.
-----Original Message-----
From: Daren Eason [mailto:[EMAIL PROTECTED]]
Sent: Friday, January 19, 2001 11:19 AM
To: [EMAIL PROTECTED]
Subject: Basic question
Hello all ,
I have been trying to get amanda to work for the last week , to no
avail. I am sure it is something simple.
I worked out all of the installation and configuration issues , however
here is the problem.
I am backing up from a centralized backup server , all of the clients
"sync" content to the server , and the backups are performed from a dump
directory on the server. I am using a sparc-5 with a raid 5 array. The
total size of the backup is around 30 gb , which theoretically should
fit on our 20/40 DLT tapes, but solaris doesn't do well honoring
compressed capacity.
The problem is this. Every time I try and run amanda , I get an error
that the dump cannot fit on a single tape , so it errors out. It also
complains about not being able to switch to an incrementatl dump - is
that from /etc/dumpdates ? (Until now , I have used 'star' to backup).
Do I need to define the changer as a manual one ??? If so , is there
documentation to show me how ? I tried changing tapes per run to 2 , but
the documentation says that if you do not define a changer , then tapes
per run should be set to 1.
Thank you in advance for your help,
Daren L. Eason, Sr.
Systems Administrator III
Client Services
Evergreen Internet, Inc.
(480)926-4500 x. 2211
http://www.evergreen.com